I currently own an 80gig intel 320 drive. I've just bought a 330 series 60gb drive which i am going to put windows 7 64 bit on. What i want to know it which ACHI drivers should i use? I will enable it in bios, then install windows onto the 60gb drive in a sata 6 slot. The 80gb drive will be for my games and is sata 2. Do i need to do anything regarding achi apart from this? Can i leave it as it is or do i need to install the intel RST drivers upon installing windows?

you'll see that the sequential write spec for the 60GB 520 with all incompressible data is 80GB/s. All SSDs that use SandForce controllers will work this way, their performance is lower with incompressible data. Also, smaller capacity SSDs have lower write performance than larger ones. Intel is one of the few that actually put the incompressible data speeds in their specs.

For the average user, more of their data is compressible than not. Try ATTO Disk Benchmark to test your 520, it does not use incompressible data for testing.